KEEPING WARM 
down does, when wet) or if they migrate, 
leaving areas of reduced insulation. On 
this score, synthetic fiber insulation ma- 
terials have a distinct advantage over 
down in that they take up relatively 
small amounts of water. 
Polarguard, patented by the Celanese 
Corporation, is another example of a 
relatively new insulation material. It 
consists of crimped continuous fila- 
ments of polyester, with fiber diameters 
also on the order of 23 microns. An 
acrylic resin binder is applied to the 
surface of the polyester for fiber stabili- 
zation and, in conjunction with the 
crimped fiber form, yields an insulation 
material that does not easily migrate and 
shift, thereby eliminating the need for 
quilting. The fiber crimp also allows the 
material to simulate the lofty character- 
istics of such natural materials as wool. 
One of the newest insulation materi- 
als is the 3M Company’s Thinsulate 
Type C system, which consists of 60 
percent polyolefin fibers and 40 percent 
polyester fibers — two different types of 
synthetic compounds. While the polyes- 
ter fibers are on the order of 38 microns 
(0.0015 inch) in diameter, the polyolefin 
fibers are of far smaller diameter, with 
most of them ranging from 1 to 3 
microns (0.00004 inch to 0.0001 inch). 
The term microfiber is probably more 
correct for describing materials of such 
fine filaments. 
The microfibers in Thinsulate C con- 
tribute a significantly greater surface 
area than thicker fibers, thereby trap- 
ping more air; as a result, the material 
has greater insulation value per unit of 
thickness. On a weight basis, however, 
both of the previously mentioned all- 
polyester synthetic materials provide 
equal insulation per unit weight. (And in 
terms of weight and thickness, down 
surpasses all three of the synthetics.) 
Undoubtedly, future developments in 
synthetic fibers will yield insulation ma- 
terials with reduced weight and bulk. 
The latter is a critical part of the cloth- 
ing problem because when a person is 
moving around in cold weather, a small 
amount of bulk can result in an exces- 
sive expenditure of energy. 
Much of the work in evaluating syn- 
thetic insulation materials under de- 
manding environmental conditions has 
been done at the U.S. Army’s laborato- 
ries at Natick, Massachusetts. Unlike 
the civilian sector of society, which can 
buy an array of products priced to fit the 
budgets of a variety of customers, the 
Army must pay primary attention to 
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PENTAX BINOCULARS 
UNSPOILED. 
There are few places left on earth that are 
unspoiled. Sri Lanka is one of them. Once 
known as Ceylon, Sri Lanka has Asia's best 
game preserves. 200 species of animals, 425 
kinds of birds and hundreds of square miles of 
leopard, elephant and sambur. 
The wild flowers of Sri Lanka include a 
dazzling display of orchids. And where else 
could you find 600,000 acres of tea gardens 
on misty mountains? 
There are 75 ways you can tour Sri Lanka. 
Ranging from 3 to 21 days. Accommodations 
begin at $5. Deluxe sells for $45. Never has 
your dollar worked harder. From shopping to 
sightseeing. 
In our ancient cities, you can enjoy 
festivals that reflect the unspoiled nature of a 
culture which dates back 3,000 years. 
Whether your visit is pleasure, business or 
a convention, our unspoiled country will spoil 
you. Just one hour from India, three hours 
from Katmandu, Bangkok and Singapore. 
Write for a color flyer and tour digest that 
includes special airfare. 
Ceylon Tourist Board/Dept. NH10 
609 Fifth Avenue, New York, NY 10017 
sri LanKa 
Pearl oj the Indian Ocean. 
Address 
City/State Zip 
Name 
95 
